1. Field of the Invention
The present invention relates to a data communication control for a network and more particularly to data communication error prevention in the network.
2. Description of the Related Art
Data communication through a network may be made using a sliding window method. A typical data communication control method using the sliding window method is shown in FIG. 1.
According to the sliding window method, a transmitter first stores a packet data into a queue data memory structure prior to transmitting the packet data to a receiver. The packet data is then transmitted with a sequence number added thereto. Referring to FIG. 1, a receiver determines whether a packet data has been transmitted (step S1), and if the data has been transmitted, the receiver receives the transmitted packet data (step S2).
The receiver next determines whether any errors occurred during the transmission of the packet data. Namely, the receiver determines whether the packet is received with the appropriate sequence number (step S3). This determination is made during the packet reception by determining whether the packet is received in the correct sequence order. If there are no errors in the received packet data, the receiver transmits to the corresponding transmitter a signal acknowledging that the packet has been completely received (step S4). Upon receiving the acknowledgment signal, the transmitter empties the packet data from the queue data memory structure, and enters another packet data to be transmitted into the queue data structure to resume the data transmission.
If the receiver determines that an error has occurred in step S3, the receiver transmits to the transmitter a re-transmission request message requesting a re-transmission of the packet data corresponding to the lost sequence number (step S5). Because the transmitter maintains the queue data structure of the previous packet data until the acknowledgment signal is sent from the receiver, the packet data requested by the receiver can be re-transmitted.
However, data communication for a network using the sliding window method as described above has the following problems. First, if more than one transmitter transmit packets to the same receiver with the same address, the receiver cannot identify the appropriate packets. As a result, the receiver may not receive a packet in the order of its packet sequence number. In such case, a large number of data flow control message generation such as packet re-transmission request messages would be generated between the transmitters thereby creating a peak congestion.
Second, although the hardware of the receiver has a great data processing capacity, the software has a far less of the data processing capacity. Thus, large amounts of transmitted data cannot be processed by the software, thereby interfering with a normal data communication.
Accordingly, an object of the present invention is to solve at least the problems and disadvantages of the related art.
An object of the present invention is to provide an efficient method for data communication control in a network.
Another object of the present invention is to provide a data communication control method which can prevent a saturation of the network load by receiving only a proper amount of data to be processed.
A further object of the present invention is to provide a data communication control method which can reduce data communication errors due to a redundancy of the transmitted addresses.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purposes of the invention, as embodied and broadly described herein, the data communication control method for a network includes determining whether a quantity of data transmitted from transmitters exceeds a first reference value; receiving the data if the quantity of the data does not exceed the first reference value; detecting a frequency of flow control message generation between the transmitters after reception of the data, and comparing the detected frequency with a second reference value; and delaying transmission of an acknowledgment signal to the transmitters if the frequency of the flow control message generation exceeds the second reference value as a result of comparison at the third step.
In the present invention, a threshold value of data which a data processing software can perform is determined and the reception of packets exceeding the threshold value is suspended. The present method utilizes a data processing software to receive all receivable packets through a data receiving equipment, while suspending the transfer of the packets exceeding the threshold value from the data receiving equipment to the data processing software.
Also, to cope with the address redundancy from the transmitters, the method according to the present invention detects the frequency of the flow control message generation such as retransmission request messages, transmission fail messages, and re-determination messages generated between the transmitters and a receiver. If the frequency exceeds a predetermined reference value, the method judges the addresses from the different transmitters as redundant, and delays the transmission of the acknowledgment messages to the corresponding transmitters, informing a user of such a situation.